Combined feed and stop valve, &amp; c.



No. 635-,|48. Patented Oct. I7, |899.

H. SCHMIDT &. G. LEIDENRDTH. COMBINED FEED AND STOP VALVE, c.

(Application led July 20, 1899.) (llo Model.)

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HERMANN SCHMIDT AND GUSTAV LEIDENROTI-I, OF HAMBURG, GERMANY.

COMBINED FEED AND STOF VALVE, ne.

SPECIFICATION forming part of Letters Patent No. 635,148, dated October17, 1899.

Serial No. 724,501. (No model.)

To all whom, t Uta/y concern.-

Be it known that we, HERMANN SCHMIDT, manufacturer, residing at 62I'Ierderstrasse, and GUSTAV LEIDENROTH, engineer, residing at 22Admiralitafstrasse, Hamburg, in the German Empire, subjects of theEmperor of Germany, have invented new and useful Im* provenients in aCombined Feed and Stop Valve with a Guide for the Return-Water Current,of which the following is a specifi. cation. i

As is well known, in the feed-water supply for steam-boilers there isalwaysa non-return valve, (feed-valve,) and between vthis valve and theboiler there is arranged a stop or cutoff valve, which can be closed forthe purpose of enabling the non-return valve to be inspected whenrequired to remedy any irregularity in the working. In connection withthis arrangement there is, however, the objectionable feature' that atthe moment when the forcing action of the feed-pump is reversed intosuction the column of water between the boiler and non return valve isthrown against the valve owing to the action ofthe higher pressure inthe boiler.- These blows given by the water occur continuously duringthe working of the feed-pump, and they are the stronger the higher thesteam? pressure in the boiler, and they notonly cause a speedydeterioration of the valve and its seat, but they are also responsiblefor the imperfect working of the valve, the disadvantageous effectincreasing directly with higher boiler-pressure and with the quantity ofwater thrown back during the change of the stroke of the pump-plunger.

According to this invention the aforementioned disadvantages areobviated in the im-` proved combination-valve by reducing the spacebetween the stopvalve and the nonreturn valve to a minimum owing to thelatter valve being arranged'in the casing of the stop-valve.Furthermore, the blow from the reduced quantity of water is avoided bycausing the return-current to flow in a direction along a guide-wallexactly central, but opposite that of the closing of the valve. In thismanner the working of the valve is noiseless -and greater durability isinsured.

line 2 2 in Fig. l.

In carrying our invention into effect the part a is connected with thefeed-pipe and the end t with the steam-boiler. The valve c of thestop-valve is adapted to be pressed upon its seat by means of thespindle CZ and hand-wheel e or to be lifted off its seat by the same toopen the valve. The non-return valve f is guided from below and above,as shown, and is formed with a double contactsurface, so as to reduceits stroke, this hav ing beenfound to be of particular advantage withregard to the motion of the returning' water relatively to thedownstroke of the non-4 return valve, as has already before beenmentioned.

The water from the feedepipe enters the valve-casing at a and flowsthrough the side passages g g', Fig. 1, into the annular space h andafter lifting the valvef passes into the spaces QI andy', Fig. l, andthence through the passageZ into the boring j, the open stopL valve c,and space t into the boiler. The v0l= ume of Water between the boilerand non-return valve thrown back at the commencement of thesuction-stroke cannot strike' against the valve, but itsline force isdirected along the guide-wall m, formed by the central space j of thevalve-casing, onto the cover 7c, while the waves which travel upwardthrough the passage Z in opposition to the downward motion of the valvef allow this 'latter to close gradually and without noise.

valve, and Fig. 2 is a cross-section along the and the stop Valve in asingle Casing forthe l opposite direction to the downwardly-moving lopurpose of reducing the Volume of water befeed-valve. tween the boilerand feed-valve at the eom- In testimony whereof We afxoursignaturesIneneement of the suction-stroke, the arin presence of two witnesses. l5 rangement being such that the line force of HERMANN SCHMIDT.

' the returning water is directed onto the Cover GUSTAV LEIDENROTH.

7c by a guide, formed by the upper wall part Witnesses: m ofthe spacejwhile thewaves, which travel E. H. L. MMMENHOFF, upward through thepassage Z flow in the OTTO W. HELLMINK.

